Question: Who is the {human} for {notable work} of {Flatiron Building}
Paraphrase: Who is the {human} for {outstanding work} of {Flatiron Building}
SPARQL (Wikidata):  select distinct ?sbj where { ?sbj wdt:P800 wd:Q220728 . ?sbj wdt:P31 wd:Q5 } 
Answer: Daniel Burnham, Frederick P. Dinkelberg